Migrate test block 10 to Dart 2.0.

tests/corelib_strong/int_round_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'package:expect/expect.dart';
-
-main() {
-  Expect.equals(0, 0.round());
-  Expect.equals(1, 1.round());
-  Expect.equals(0x1234, 0x1234.round());
-  Expect.equals(0x12345678, 0x12345678.round());
-  Expect.equals(0x123456789AB, 0x123456789AB.round());
-  Expect.equals(0x123456789ABCDEF, 0x123456789ABCDEF.round());
-  Expect.equals(0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF,
-      0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF.round());
-  Expect.equals(-1, -1.round());
-  Expect.equals(-0x1234, -0x1234.round());
-  Expect.equals(-0x12345678, -0x12345678.round());
-  Expect.equals(-0x123456789AB, -0x123456789AB.round());
-  Expect.equals(-0x123456789ABCDEF, -0x123456789ABCDEF.round());
-  Expect.equals(-0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF,
-      -0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF.round());
-
-  Expect.isTrue(0.round() is int);
-  Expect.isTrue(1.round() is int);
-  Expect.isTrue(0x1234.round() is int);
-  Expect.isTrue(0x12345678.round() is int);
-  Expect.isTrue(0x123456789AB.round() is int);
-  Expect.isTrue(0x123456789ABCDEF.round() is int);
-  Expect
-      .isTrue(0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF.round() is int);
-  Expect.isTrue(-1.round() is int);
-  Expect.isTrue(-0x1234.round() is int);
-  Expect.isTrue(-0x12345678.round() is int);
-  Expect.isTrue(-0x123456789AB.round() is int);
-  Expect.isTrue(-0x123456789ABCDEF.round() is int);
-  Expect.isTrue(
-      -0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF.round() is int);
-}